The cause of bone spurs varies, but most scholars believe that the pressure in the intervertebral disc space is elevated by the degeneration of the nucleus pulposus, resulting in traction on the surrounding anterior or posterior longitudinal ligaments, etc. This traction can directly stimulate local hematoma formation in the subligamentous space, at which point fibroblasts become active and gradually grow into the hematoma, gradually replacing it with granulation tissue. If there are new tears and new hematomas in the microvasculature of this space, the same vertebral segment may show a microscopic view of old and new lesions coexisting. As the hematoma mechanizes, ages, and deposits calcium salts, it eventually forms a bony flab (or spur) that protrudes toward the spinal canal or toward the anterior edge of the vertebral body. This bone flab can grow in size and hardness through hemorrhage, mechanization, ossification, or calcification due to repeated local trauma, continued stretching of the surrounding ligaments, and other factors. Bone spur formation can be seen in any vertebral segment, but is most common in cervical 5, cervical 6, and cervical 4, which are subjected to greater external forces, and from the same vertebral segment, the first occurrence at the barbels is often the posterior edge of the vertebral body.